A new, clean filter medium for dust separation always begins with an initial phase in which dust separation can be described according to the principle of depth filtration in the given medium. If dust separation is carried out on the given filter medium for a sufficiently long time, a dust cake can form after a completed clogging phase. This is often a gradual process. For typical depth filter applications, the longest possible clogging phase with a moderate increase in pressure loss is advantageous. In contrast, when using surface filters, the cake-forming filtration after the shortest possible clogging phase is desirable. While the filtration kinetics of a depth filter can be investigated using various model approaches (dendrite growth model or fiber growth model) to describe particle separation in the clogging phase, the transition to surface filtration by continuing the same model calculation is not yet possible, as the dust cake growth, which simultaneously means the expansion of the initial packing, is not achieved by the underlying separation theory, but by a separate add-on model. So far, there is no coherent model for a holistic view of the entire filtration process.

In this paper, a multi-layer model with offset for dust cake growth is presented, which enables the description of particle separation during the entire filtration process without a separate add-on model for switching between depth and surface filtration. The results of the model calculations are compared ...